Suppression of rectification at metal-Mott-insulator interfaces

Abstract

Charge transport through metal-Mott-insulator interfaces is studied and compared with that through metal-band-insulator interfaces. For band insulators, rectification has been known to occur owing to a Schottky barrier, which is produced by the work-function difference. For Mott insulators, however, qualitatively different current-voltage characteristics are obtained. Theoretically, we use the one-dimensional Hubbard model for a Mott insulator and attach to it the tight-binding model for metallic electrodes. A Schottky barrier is introduced by a solution to the Poisson equation with a simplified density-potential relation. The current density is calculated by solving the time-dependent Schrödinger equation. We mainly use the time-dependent Hartree-Fock approximation, and also use exact many-electron wave functions on small systems for comparison. Rectification is found to be strongly suppressed even for large work-function differences. We show its close relationship with the fact that field-effect injections into one-dimensional Mott insulators are ambipolar. Experimentally, we fabricated asymmetric contacts on top of single crystals of quasi-one-dimensional organic Mott and band insulators. Rectification is strongly suppressed at an interface between metallic magnesium and Mott-insulating (BEDT-TTF)(F${}_2$TCNQ) [BEDT-TTF=bis(ethylenedithio)tetrathiafulvalene, F${}_2$TCNQ=2,5-difluorotetracyanoquinodimethane].

6 pages, 5 figures, accepted for publication in Phys. Rev. B

References in corpus (5)

• Carbon Nanotubes as Schottky Barrier Transistors
• Drain Voltage Scaling in Carbon Nanotube Transistors
• Breakdown of a Mott insulator -- non-adiabatic tunneling mechanism
• Interfaces of correlated electron systems: Proposed mechanism for colossal electroresistance
• Mechanism of Ambipolar Field-Effect Carrier Injections in One-Dimensional Mott Insulators

Cited by in corpus (12)

• Engineered Mott ground state in LaTiO${}_{3+\delta }$/LaNiO${}_3$ heterostructure
• Nonlinear current response of an isolated system of interacting fermions
• Crossover from bias-induced to field-induced breakdowns in one-dimensional band and Mott insulators attached to electrodes
• Density of States and Magnetic Correlations at a Metal-Mott Insulator Interface
• Nonequilibrium Green's-Function Approach to the Suppression of Rectification at Metal--Mott-Insulator Interfaces
• Peltier effect in strongly driven quantum wires
• Analytical study of non-linear transport across a semiconductor-metal junction
• Transport in Conductors and Rectifiers: Mean-Field Redfield Equations and Non-Equilibrium Green's Functions
• Quasi-particle propagation across semiconductor-Mott insulator interfaces
• Roles of Potential Gradient and Electrode Bandwidth on Negative Differential Resistance in One-Dimensional Band Insulator
• Charge order and possible bias-induced metastable state in the organic conductor β-(meso-DMBEDT-TTF)2PF6: effects of structural distortion
• Energy current and energy fluctuations in driven quantum wires